Question

Suppose we want to estimate the 90% confidence interval of difference between mean age of university students in Minnesota and Wisconsin. For this we took a random sample of 10 students from Minnesota and another sample of 15 students are taken from Wisconsin. Suppose we found mean age of Minnesota students 23 years with sample standard deviation 2.3 years. also we found mean age of Wisconsin students 22.5 years with sample standard deviation 1.6 years. What is the critical value tα/2?

2.017
	1.714
	1.96
	1.285
	2.98

Answer 1

i am denoting Minnesota students by group 1 and Wisconsin students by group 2.

necessary data are:-

degrees of freedom be:-

[here, we are assuming equal variance.]

the critical value for alpha = 0.10, df=23, both tailed test be:-

[ using t distribution table ]

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